A wildfire burning near Nogales is 50 percent contained, forest service officials said.

The fire was reported at about 11 a.m. Tuesday about 7 miles west of Nogales, Ariz. It started in Mexico and moved north across the border and into the Coronado National Forest. So far 50 acres of brush and grass have burned, a forest service official said in a news release.

The cause of the fire is unknown.

Two fire crews, on engine and various overhead fire suppression tactics are being employed to control the blaze.